~~NOCACHE~~
====This is Steve's outline for a Blockchain talk to Lexington Computer Group====
This is a work in progress.
[[blockchain_notes]]

How are Bitcoin and blockchain related?  Bitcoin //uses// blockchain.  Blockchain is used for Bitcoin, and much, much more.  \\ 
This talk gives a simplistic overview of blockchain.

Concepts
  * Data store (holds transactions)
  * Replication (many people hold the chain)
  * Cryptography and digital signatures
  * Immutable (hard to change history and changes are detectable)

  - Use of Blockchain for ledgers
  - Hashing basics
  - Public Key Infrastructure basics
  - Block contents
  - Add new block
  - Need for Mining


====Overview - How does blockchain work?==== 
(This section has material copied directly from [[https://www.ibm.com/blockchain/what-is-blockchain]])

  * As each transaction occurs – and the parties agree to its details – it’s encoded into a block of digital data and uniquely signed or identified.
  * Each block is connected to the one before and after it — creating an irreversible, immutable chain.
  * Blocks are chained together, preventing any block from being altered or a block being inserted between two existing blocks.

Difference between blockchain and Bitcoin
  * Bitcoin: unregulated, digital currency.
  * Blockchain: is used by Bitcoin (and blockchain used for many other things)

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